Battery charging system



Aug' 8, 1944' J. VAN VULPEN r-:TAL 2,355,488

BTT ERY CHARGING SYSTEM Filed Jan. 7, 194s U5@ WM 02% Patented Aug. 8, 1944 BATTERY CHIARGING SYSTEM John Van vulpen and Everett H. Burgess, Chicago, Ill., assignors to Vapor Car Heating Company, Inc., Chicago, Ill., a corporation of New York Application January 7, 1943, Serial No. 471,530

3 Claims.,

This invention relates to a new and improved battery charging system. more particularly to such a system wherein the generator or other source of charging current is so controlled as to vary the rate at which current is supplied to the battery in accordance with changes in the internal temperature within the battery that is being charged.

Brieiiy described, an immersion type thermostat is positioned within the battery and acts through suitable relays to vary the output from the generator (and consequently the input to the battery) in accordance with changes in the prevailing temperature within the battery, If the temperature within the battery is below a predetermined minimum-for example 50 F.- the charging rate is reduced to a minimum, whereas this charging rate is again reduced to this minimum above a predetermined maximum battery temperature (for example 95). At any battery temperature between the predetermined minimum and maximum, the charging rate is increased to the efficient maximum.

The single view shown in the drawing is a partial elevation and partial wiring diagram showing the control mechanism and thermostat, together with the generator, in combination with a battery that is being charged.

The battery A is shown with its terminals I and 2 connected, respectively, with the leads 3 and 4 extending from the output terminals 5 and 6 of the generator C. The field l of generator C is connected, in serieswith a control resistance 8, across the mains 3 and 4. The resistance is divided into three sections, in series with one another, indicated at y and z, respectively. The extremities of the first resistance section a: are connected by the wires 9 and i0 with a pair of fixed terminals and i2. Similarly, the third section z is connectedat its respective ends by wires I3 and I4 with the fixed terminals i and I6.

The mercury tube thermostat B when inserted in operative position within a battery A, as shown in the drawing, will have its bulb immersed in the battery so as to respond to the internal tem- Derature thereof and the mercury column I1 will rise in the stem so as to successively engage the three iixed contacts I8, I9 and 2|) fixed at dliierent elevations in the stem. The lower contact i8 is so positioned as to engage the mercury column i1 at any normal temperature, and this contact is connected with the generator main 3 through wire 2|.

engaged by the mercury column at a. predeter- The second contact I9 is mined minimum battery temperature (for exam ple 50), this contact I! being connected through wire 22 with one end of the solenoid coil S1, the other end of this solenoid coil being connected through wire 23, resistance 24 and wire 25 with the other generator lead 4. In short, if Vthe temperature within the battery A is at or above 50 F. the solenoid S1 will be energized through these thermostat contacts, and pull down the core 2l and stem 21 so as to lower the bridging contact 2l into engagement with the xed contacts and I2 so as to complete a short circuit through wires 9 and I0 around the resistance x. At the same time, when sole'- noid Si is energized, the second bridging contact 29 on the stem 21 will be lowered into engagement with a second pair of iixed contacts- 30 and 3| so asto complete a circuit from main lead 3 through :wire 32, contacts 30, 29 and 3|, wire 33, signal iight 84 and wire 35 to the main 4, the light 34 giving a visible indication that the temperature within the battery A is above the predetermined minimum.

Whenever the solenoid Si is de-energized (for example when the battery temperature falls below the predetermined minimum of 50) the core 26 and stem 21 will be elevated by the spring 36 so asto break the contacts 28 and |2 'which short-circuit the fieldv resistance :if and to also break the contacts 30, 29 and 3| so as to de-energize the signal lamp 34.

Whenever the temperature Within the battery A' reaches a predetermined maximum so that mercury column il will engage the upper thermostat contact 20, another circuit will ilow from main 3 through wirel 2| and the thermostat through contact 20 and wire 31 to and through the solenoid coil Sa and thence through wire 38, resistance 29 and wire 40 to the main 4. When the battery temperature is belowthe maximum of and the solenoid S2 is de-energized, the core 4| and stem 42 will be lifted by the spring 43 so as to bring the movable contact plate 44 into engagement with the pair of fixed contacts i5 and I6 and thus complete a short circuit through the wires I3 and I4 around the resistance section z. In other words, as long as the battery temperature is below 95, the resistance z will be short-circuited, but as long as' the battery, temperature is above this maximum and solenoid S: is energized the bridging contact 44 will be drawn down so as to break the short-circuit and the resistance section z will remain in Series with the eld coil When the battery circuit is above the maximum of 95 and solenoid Sz is energized. the bridging contact 45 will be pulled down so as to engage another pair of fixed contacts 48 and 41 and thus complete another signal circuit through the lamp 48.

Assuming now that the generator C is suitably driven and that the battery A to be charged is connected with the generator output lines I and 4 and the thermostat B mounted in the battery so as to respond to the prevailing battery temperature, the other parts will then assume the several relative positions indicated in the drawing. Since the battery temperature is now below 50, both solenoids Si and Sn will be de-energized and the resistance section z will now be short-circuited. leaving the resistance portions :z: and u of the total ileld resistance 8 in series with the field 'l so that a comparatively weak charging current will flow through the battery. In the event that the temperature within the battery rises above 50 F. both contacts I8 and I8 of the thermostat will be engaged by the mercury column l1 and a circuit will flow through solenoid Si so that a short-circuit will be completed around the resistance portion x. Since the resistance portion z remains short-circuited, only the portion y of resistance 8 remains in circuit with the field l and consequently a. comparatively strong charging current flows through the outlet mains l and 4 into and through the battery A. This strong current will continue until the battery temperature rises to and above 95 F., whereupon the solenoid S2 is energized so as to break the shortcircuit through wires I3 and Il, whereupon the section z of resistance 8 is restored to the Ileld circuit. Since the portions :c and z of resistance 8 are of substantially the same size, the strength of the entire eld circuit will now be substantially the same as it was when the battery temperature was below 50.

In short, an eflcient charging current will be supplied to the battery while the battery temperature is between 50 F. and 95 F.. but as long as the battery temperature is below 50 or above 95 the eillciency of the charging current will be considerably reduced. It the battery temperature is below the minimum or above the maximum, these facts will be shown by the signal lights Il and 4.8, respectively.

The operation of the system is entirely automatic, it only being necessary to attach the battery A between the charging wires 3 and 4 and to insert the lthermostat B within the battery so as to have it register the temperature thereof.

We claim:

1. A battery charging system comprising a generator comprising a field and a variable resistance in series with said ileld, means for connecting the battery with the generator, and means for increasing said resistance and thereby reducing the charging rate of the generator whenever the temperature within the battery is below a predetermined minimum or above a predetermined maximum.

2. A battery charging system comprising a generator comprising a iield and a variable resistance in series with said field, means for connecting the battery with the generator, and means comprising an immersion thermostat for increasing said resistance and thereby reducing the charging rate o1' the generator whenever the temperature within the battery is below a predetermined minimum or above a predetermined maximum.

3. A battery charging system comprising a generator, means for connecting the battery with the generator, an immersion type thermostat adapted to be associated with the battery and comprising a contact adapted to be engaged at a predetermined minimum battery temperature, a second contact adapted to be engaged at a predetermined maximum battery temperature, said generator comprising a eld and a resistance in seqries therewith for maintaining a reduced charg- 

